Define scale... People usually use that word talking about something completely different with bitcoin.
Exactly. There are several varieties. It's difficult to ascertain whether the OP was referring to all or only some of these:
A decent amount of scaling can come from optimisations and efficiency savings - squeezing a larger quantity of transactions into the space we currently have available. This is generally considered to be the least contentious option. We'll hopefully see a few of these in the not-too-distant future.
Willing users can opt to send smaller transactions off-chain, sacrificing some security for speed and cost-effectiveness - leaving more space in blocks for significant sums that require the greater security provided by on-chain transactions. Contentious to some, but it's a moot point. Still in a fairly early developmental stage. Currently more suitable for the tech-savvy "power users", rather than less experienced ones. If successful, it could have the largest impact of all.
We can increase blockweight if absolutely necessary - a potential sacrifice to the decentralisation of the network in order to achieve greater throughput. Highly contentious to many. Difficult to achieve consensus on. Generally considered a last resort.